New research

Three White House charts showing why the world needs to take immediate action on climate change

  • 30 Jul 2014, 13:40
  • Mat Hope

President Obama has taken significant, if limited, steps to try and curb the US's emissions and tackle climate change. A new White House report explains why he appears to be acting with a sense of urgency: "delay is costly".

Yesterday, the White House's Council of Economic Advisers released a  report suggesting a 10 year delay could increase the cost of taking climate action by 40 per cent, as the world would have to take larger steps to curb emissions down the line. Furthermore, each degree of warming could lead to billions of dollars worth of additional damage, it says.

Here's three charts from the report showing why the council says policymakers need to act now.

Additional damage

The more the world warms, the more damaging the  impacts of climate change are likely to be - from more intense weather events, to diminishing crop yields and species migration and extinction. All these things have an economic cost, even if it's sometimes  hard to define.

And the council's study says the costs will rise as the world warms - as the blue bars on this graph show:

Additional Costs Chart

The White House report uses a model by Yale economist Bill Nordhaus to put a number on the potential impact of additional warming.

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Air pollution and climate change could mean 50 per cent more people going hungry by 2050, new study finds

  • 30 Jul 2014, 12:20
  • Roz Pidcock

The combination of rising temperatures and air pollution could substantially damage crop growth in the next 40 years, according to a new paper. And if emissions stay as high as they are now, the number of people who don't get enough food could grow by half by the middle of the century.

Burning question

Feeding the world's rapidly growing population is a serious concern.

Research shows  rising temperatures are likely to lead to lower crop yields. Other work suggests air pollution might reduce the amount of food produced worldwide. But nobody has considered both effects together, say the paper's authors.

The two effects are closely related as warmer temperatures increase the production of ozone in the atmosphere, the paper explains. 

The  new study looks at global yields of the four principle food crops - wheat, rice, corn and soybean - and how they're expected to change by 2050 under different levels of future emissions.

Together, these provide nearly  60 per cent of all the calories consumed by humans worldwide.

Global losses

The maps below show some of the results.

The top panel shows an optimistic scenario in which greenhouse gases stabilise at 630 parts per million (ppm) by 2100. For reference, we're at about 400 ppm now.

The team compared this with what might happen if greenhouse gases continue to rise as rapidly as they are now. That's the bottom panel.

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Why measuring fugitive methane emissions from shale gas production matters

  • 24 Jul 2014, 14:40
  • Mat Hope

As an ever-increasing number of countries consider exploiting their shale gas resources, and researchers scramble to understand what a production boom could mean for the climate, two new pieces of research appear to come to opposite conclusions.

What is the climate impact of shale gas?

Since gas has about half the emissions of coal when it's burned for electricity, it has been touted as  a 'bridging fuel' for countries seeking to decarbonise their economies to use as a stop gap on the way to a low carbon electricity system.

But as we've  explored before, scientists are struggling to establish the full impact of increased shale gas production on the climate, due to methane that escapes during the extraction process - known as fugitive methane emissions.

Two papers released this month examine what the actual climate impact of natural gas is. At first glance they seem to show opposite things. The graph on the left, taken from a paper by Robert Howarth appears to show natural gas electricity generation emissions - the towering left bar - can be much higher than coal's. The second graph, from  Heath et al, appears to show the opposite - that coal's generation emissions (on the left) are much higher than those from both conventional and shale gas.

Howarth Vs Heath Coal And Gas Emissions

Both papers examine the 'lifecycle emissions' of the fuels: the amount of gas emitted from extraction to combustion. So why is there such a large discrepancy between two papers?

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